|Season|Network|Play-by-play|Color commentator(s)|Sideline reporter(s)|
|---|---|---|---|---|
|1969|CBS|Jack Whitaker|Frank Gifford and Don Perkins||
|1968|CBS|Ray Scott|Paul Christman|Frank Glieber|
|1967|CBS|Frank Glieber|Frank Gifford||
|1966|CBS|Chuck Thompson|Tom Brookshier||
|1965|CBS|Frank Glieber (first half) and Chuck Thompson (second half)|Pat Summerall||
|1964|CBS|Jack Drees (first half) and Earl Gillespie (second half)|Frank Gifford||
|1963|CBS|Ray Scott (first half) and Ken Coleman (second half)|Frank Gifford||
|1962|CBS|Chris Schenkel (first half) and Ray Scott (second half)|Warren Lahr||
|1961|CBS|Chris Schenkel (first half) and Van Patrick (second half)|Johnny Lujack||

Question: how many seasons of play-by-play did chris schenkel and chuck thompson host combined?
Answer: 4